Centrifugal casting machine



J. FREI, JR

CENTRIFUGAL CASTING MACHINE April 28, 1953 2 SHEETSSHEET 2 Filed June 2,1947 & 1% N fizwerziar: Jv/m F361), Jr.

/ QQQ Patented Apr. 28, 1953 UNITED STATES PATENT OFFICE CENIRIFUGALoAsmNo MACHINE JohnFreLJn, Chicago, Ill. Application 'Junejz, 1947,Serial No. 751,655

6 :Claims.

My invention relates to centrifugal casting of metal and moreparticularly to a centrifugal casting machine.

It is an object of my invention to provide a centrifugal casting machinein which the use of less centrifugal force is required than is necessaryin the usual centrifugal casting machines operating about a verticalaxis. A centrifugal casting machine which operates about a vertical axisgenerally is required to lift the metal in the crucible from a lowerlevel to a higher level at whichthe outlet of the crucible is located,before the metal will be cast therefrom into the mold. This liftingaction requires the exertion of con siderable force and thatnecessitates higher angular velocities. More time may also be requiredto complete the casting operation. In the accomplishment of the abovementioned object I provide a centrifugal casting machine which isarranged to rotate about a'horizontal axis with the mold and crucibleinitially being vertically aligned and wherein the outlet of thecrucible extends vertically and the mold is positioned radially beyondsaid outlet in casting relationship. "In

such arrangement the first half revolution of the I casting machinedelivers the molten metal in the crucible to the mold and thereforespeeds up the casting operation. Only sufficient centrifugal force needthereafter be provided to retain the metal in the mold until it has set.

It is a further advantage of my invention, wherein I dispose thecentrifugal casting apparatus on a horizontal axis-that access maybe hadmore readily to all portions of the casting apparatus than is possiblewhen it is disposed about a vertical axis. It is still a furtheradvantage that the centrifugal casting machine of my invention requiresfar less floor space than that occupied by centrifugal casting machinesof known types.

It is another object of my invention to provide a centrifugal castingmachine which is adapted to accommodate molds of differentsizes-withoutthe necessity of providing different sizes of cradles forholding the different sizes of molds. No special adjustments or extraparts are necessary at any time to accommodate molds of various sizes.

it is another object of my invention to provide, in conjunction with thecentrifugal casting machine, heating means which will heat the metal in"the crucible to high temperatures rapidly and with a minimum of heattransference to adjacent objects. In the casting machine of my inventionthe heating means is so disposed relative to the rotatable apparatus ofthe casting machine that immediately after the metal in, the crucible isheated to the desired temperatureit can be cast into "the moldcentrifugally so that there is no delay occasioned which will chill the,metal,,o.r which will chill the mold when a pro-heated moldis-employed.

It is another object of :my inventionto pro vide sa iety means for thecentrifugal casting machine of my inventionwhereby, during the castingoperation, the rotating mechanism is entirely enclosed. In thisconnection I preferably employ a movable closure member which, when ithas been moved :to cover the open side of the casting apparatus adjacentthe operator, automatically starts the driving :means for the r0 tatahleapparatus of said casting machine. Also, when it is desired to cease{the casting operation, movement of the closure element away from thefrontof the rotatable apparatus automatically shuts off the drivingmeans for said apparatus.

It is a further advantage of my invention that, following the castingoperation, movement of the crucible away from the mold to release thesame from its casting position simultaneously returns the crucible tothe position wherein it may be heated by the heating means.

Other objects, uses and advantages of :my invention will become apparentfrom the following description when taken with drawings in which:

Figure 1 is a front elevation of the centrifugal casting machine of myinvention'with portions broken away;

Figure 2 is a horizontal, sectional view on the line 2 2 of 21:; and

Figure 3 is a vertical, sectional view on the line 3--'3 of Figure 1illustrating the casting machine in larger scale.- Likereferenoenumerals have been employed in the several views to indicatethe same or similar elements.

Referring now to Figures 1, '2 and 3 it will be seen that thecentrifugal casting machine illustrated in the drawings is indicatedgenerally by the reference numeral It. This centrifugal cast ing machinecomprises a vertically extending supporting structure formed of brickand angle iron, the base, indicated generally by the refereence numeral[2, being built up of brick, and the circular or arched portion,indicated generally bythe referencenumeral i ibeing formed of bricksupported by angle iron 18. It will be understood that other materialscould be employed in the construction of the base I 2 and arched portheaccompanying Secured to the back of the centrifugal casting machine I9is a stationary supporting plate I8 which has a circular opening 29. Therotatable portion of the casting machine, indicated generally by thereference numeral 22, comprises a circular rotatable plate 24 which issecured to an annular flange 26 of a ring 28. The diameter of ring 28 issuch that it fits within the circular opening 29 in the back supportingplate I8 with sufficient clearance so that it may be rotatable relativeto the plate I8 and find bearing support therein. On the right hand sideof supporting plate I8 (see Figure 3) an annular member 39, having agroove 32, is secured to the outer side of ring 28and serves to keep thering 28 from becoming disassociated from the plate I8.. A V-belt 34 isadapted to ride in groove 32. of the annular member 36 and to extendtherefrom and about a driving pulley wheel 36 which also has a V-shapednotch 38 to accommodate the belt 34.

' Pulley wheel 36 is carried on a shaft 49 for rotation therewith. Shaft49 is supported in bearings 42 and 44 which are secured to the base I2of the centrifugal casting machine In in a passageway 46 which extendsthrough said base from its back side to its front side. At its otherend, shaft 49 has keyed to it, as by key 41,. a larger pulley wheel 48having a. V'shaped notch 59 in which a V-belt 52 is adapted to ride.Belt 52 extends from the pulley wheel 48 about a small pulley wheel 54directly connected with the driving mechanism 56 for the rotatableportion 22 of the centrifugal casting machine [8. The driving mechanism56 is an electric motor, but it will be apparent that other drivingmeans may be substituted therefor. It will be observed that the largepulley wheel 48 at the front of the centrifugal casting machine has aplurality of hand grips 58 by means of which the operator may manuallyshift the rotatable portion 22 of the casting machine when the drivingmechanism 56 is shut off. The purpose of such manual shifting of therotatable portion 22 will be explained hereinafter.

The circular revolving plate 24 (which is driven from the drivingmechanism 56 through the pulley wheel 54, belt 59, pulley wheel 48,shaft 49, pulley wheel 36, belt 34,'annul'ar member 36 and ring 28) hassecured to its front face 69 a supporting structure, indicated generallyby the reference numeral 62, which comprises a pair of parallel sidemembers 66 and a transverse end wall 68 which is positioned near theperiphery of the circular rotatable plate 24.

The side members 66 each have a longitudinally extending slot 19.Positioned in each slot 19 is a lug 12 which is secured to a centrallyapertured platform 14, which platform serves as a holder and carriagefor a crucible 16. The platform 14 is guided in its movement by theslots 19. On the outer side of each side member 66 there are a pair ofidler pulley wheels I8 and 89 which serve to guide a cable 82 which isconnected at one end to screw eye 84 in the top of a lug I2 and which,at its other end is connected to a spring 85 and then to a cross bar 86.The bar 86 having a handle 81 at each end interconnects the two springs85 and their respective cables 82. Intermediate the ends of each cable82 there is interposed, in series, a sprgcket chain 88 which is adaptedto engage the teeth of a sprocket Wheel 99, carried by side member 66,the sprocket wheels on each side of the supporting structure 62 beinginterconnected for simultaneous rotation by a shaft 92. It willtherefore be seen that movement of the cross bar 86 by the operator in adownward direction to a position indicated in Figure l by the dottedline position of the bar will result in a raising of the platform 14 toits dotted line position in Figure l. The platform 14 will by its ownweight tend to descend and raise the cross bar 86 unless said bar isheld in its lowered position. There is therefore provided along an edgeon each side member 66 a series of downwardly inclined teeth 94 underwhich the cross bar 86 may be hooked. Consequently the platform 14,which serves as a carriage for the crucible '16, may be ad usted to anydesired height by downward movement of the cross bar 86 followed byengagement of said bar with teeth 94. If the exact level desired forplatform 74 does not position the cross bar 86 exactly in alignment withteeth 94 on the side members 66, springs connected to thecross bar 86will permit of adjustment of the position of the cross bar so that itmay engage the teeth. The advantage and purpose of this ad ustment willbe pointed out at greater length hereinafter.

The purpose of employing the sprocket chains 88 and interconnectedsprocket wheels 99 intermediate the ends of the respective cables 82 isto maintain the platform 14 in horizontal position and to exert equallifting force on its opposite sides even when the force supplied to thecross bar 86 may be greater on one side than on the other. It will beseen that pulling down on one side of the cross bar 86 will cause thecable 82 connected to that side of the bar to drive the sprocket wheel99 on that side and said sprocket wheel by being interconnected by theshaft 92 to the other sprocket wheel 99, will drive the other cable 82at the same rate so that there will be an automatic adjustment of thisunbalanced force. Consequently, the platform 14 will not be cocked fromits horizontal osition, which movement might result in jamming of theplatform between the side members 66 and shifting of the mold-containingflask 95 which is resting on the platform.

The central aperture 96 in the platform 14 is enlargedas at 98 in orderto provide a seat for the flange of crucible 16. The crucible may beeasily lifted out of the aperture 96 at anytime desired. In order toheat crucible I6 I supply in conjunction with the centrifugal castingmachine heating means indicated generally by the reference numeral I99,which heating means in its preferred form comprises an induction coilI92 havin its leads I94 and I96 extending through a central aperture I96in the rotatable plate 24. If desired, the induction coil I92 may besupported independently of the centrifugal casting machine I9 and doesnot rotate with the rotatable portion 22 of machine I9.

From Figure 3 it Will be seen that the cross bar 86 Whichis manuallycontrolled by the operator may be engaged with the upper teeth 94carried by the side members 66 so that the platform 14 is positionedimmediately above the induction coil I92. This permits the crucible 16carried by the platform 14 to be surrounded by the induction coil and tobe heated, together with its contents, by said coil. When the metal inthe crucible is heated to the desired temperature it may be withdrawnimmediately from the induction coil I92 by pulling downwardly on thecross bar 86 since such downward movement will draw the platform 14upwardly and carry the crucible with it. In use, a flask 95 containing amold is positioned with ts pour ng sprue adjacent. the outlet of theassesses crucible 16 and in alignment therewith :as soon as the metal isheated to the propertemperature. At that time downward movement of thebar 86 'by the operatorcarries the crucible and-superimposed fiaskupwardly to the dotted line position shown in Figure 1 wherein the'fiaskisiheldnrmly in place between the end, or transverse, wall 68 of thesupporting structure 52 by means of the platform M which is securedin anupper osition by positioning of the cross bar .86 beneath the teeth 94adjacent said bar. In actual practice the bar 86 is drawn down until theplatform 14 will go no farther in an upward direction andthen the crossbar "is moved downwardly stillfar'ther in order to have the springs"85under "tension when thebar 86 is hooked under the teethlll.

During the operation of the centrifugal casting machine Ill the largepulley wheel 68 at the front of the centrifugal casting machine isrotating and might, by its handles 58, strike an operatorstanding-nearby. Consequently, in the preferred form of my invention Ienclo e the pulley wheel 48 in a housing I It which covers-theirontofthe wheel and its-sides and permits access to the handles of the wheelonly at its upper side-by "means of the opening H2 in said housing Hi).The opening H2 is of sufficient size that a series of handles 58 011 thepulley wheel 48 may beengaged-by the operator, when the driving meansfor the centrifugal casting machine is inoperative, so as to positionthe rotating plate 24 with the supporting strum ture 62 extendingvertically as shown in the drawings'. A mark II l on the supportingangle iron .IS atthe'top of the arched portion .I-d of castingmac'hinelmin cooperation with the pointer W on the margin of'therotatable plate 24, :permits the operator. to, vertically align thesupporting structure .52 by means of the handles 58 on the pulley wheel48 when the driving means 55 has been shutoff.

To further protect theloperator of the centrifugal casting machine II! Iprovidea movable door I I8, carried in. upper'and'lower slides I2!) andI22, respectively, which door or closure member may be positioned overthe front of the-centrifugal castingmachineso that access may-not be hadto the rotating parts during operation of the oasting machine. in thepreferred formof myrinvention the --movable door has a contact button 24at its upper left-hand corner, as viewed in Figure a which contactbutton engages a control button 1.2.6 of a switch .-I28. :Switch I28governs the operation of the driving-means so and when the door lzI-fiis moved to the left, as viewed in Figure 1, to cover the rotatingportions of the centrifugal castingniachine I of the-button .124 of door.I I8 willpress theoontrol button 126 of switch I28 and close-thecontacts of said switch, whereupon driving means 56 is set in motion todrive the casting machine. .At the end of thepredeterminedperiod ofrotation the door I I8 is moved to the right, as viewed in Figure :1whereupon the control button 26, containing a springelement (not shown),is released and breaks the circuit by which the driving means isconnected to asource of power. With the door withdrawn fromiii-frontier" the rotatable portion .22 of the centrifugal castingmachine i ll theoperatormaysthen vertically align the supportingstructure 82 connected with the rotatable plate 24 by means of thehandles 58011 the pulley wheel-.48.

The method of my inventionma-y beparried out byother apparatus than.that*-.shown, but it will be lllflddlfStOOd' from .thedescription ofthe particular apparatus illustrated the drawings,

6 The" centrifugal casting machine .of-my invention is particularly welladapted for repeatedrrapil casting operations and-may be advantageouslyemployed in connection'with a furnace such as that shown in my copendingapplication Serial No; 743,745,;fi1ed April "25, 1947, wherein heatedflasks are continuously delivered at a desired rate for transfer-to thecentrifugal casting machinea-t the time when the metal in the cruciblehasbeen heated to the desired temperature. When the flask containing themold and the crucible containing the metal have both reached'thedesiredtemperature positioningthem together at "that time will result in aminimum loss of heat-from the metal and'mold and will result in a bettercasting, assuming the casting operation may take place as soon as themold and crucible are posi tioned in casting relationship. The,centrifugal casting machine of my inventionis soconstructed as topermit oasting to take place almost instantaneously" following alignmentof the mold and crucible in casting relationship. This will peterterunderstood by a description of the'operation of my machine.

Assuming that the driving means 56 forthe centrifugal casting machineIll is inoperative and that the door -I It is withdrawn from thefront-oftherotatable portion'ifi of the casting machine, the operator will firstposition the supporting structure 62, which is carried bythe rotatableplate 24, in vertical alignment so that-the-pointer Ilfi on therotatable plate 2d will be opposite the marker I It on the archedportion Id of the cast-'- ing machine. At this time the platform I4would normally be in its lowermost position, as illustrated in Figure 1,wherein it is immediately above the induction coil I02 and the manuallycontrolled cross bar 86 will be engaged with the upper teeth 94 whioharecarried'by the side members 66 of the supporting structure'62.Ifacrucible such as crucible I6 is notalready positioned in the centralaperture 95 of the plate 14 the operator will there insert the crucibleand it will then be encircled by-the'induction coil I02. The next stepwill be to fill the crucible with metal which is to be melted and thento start the induction coil I82 to heat the crucible-and metalcontainedtherein. ;At the end of a predetermined heating 'period,.oratsuch time as the operator observes thatthe metal appears to beproperly heated, a preheated .fiask 9.5 containing a mold will bepositioned on platform '14 .with the pour, ing sprue .of the moldpositioned opposite .to and .in vertical alignment with the ,outletofcrucible l6 and thelinduction coil will be.'shut-ofi. The .0131- eratorwill immediately grasp, the .cross bar 1861b? its handles 87 and will.pullit downwardlmflthereby raising the mold andcrucible away from theinduction .coil and toward the end wall 68 orthfe supporting structure52 so that the .fiask,9.51con taining the (mold-will be heldfirmly-between/said end wall 68 and theplatiorm Flt. -When-;the,-flaskengagestheend wall 68 the operator will continue to draw downwardly onthecross bar 86, thereby stretching the springs 85,.and will .thenhooknthe cross bar under the teeth =94 carried by the-side members 66.This movement takes but 12. second or two and immediately thereafter,the operator will move thedoor lgIj-t to the leitosviewedinsfiigvure 1whereupon its contact button 124 depress the control button IRE :of:switch 1I2B :and

start the driving 'mechanism'fifirunctioning.' This will cause:thepulley :wheel 254 of the drlving mechanismfifi to .:rotate an'd'willcausetherotat zable plater'saand v.itsoattached :supportingwstrue ,tureGIcarryingJthe mold and crucible, torotate by-reason of the drivingmeans interposed between pulley wheel -54 and the rotatable plate 24. Onthe first half revolution the metal will be poured into the mold andthereafter the rotatable portion 22 of the centrifugal casting machineIt) will continue to be rotated at a speed sufficient to keepth'e metalin the mold by centrifugal action until the metal has set. High speedsof rotation are unnecessary with my centrifugal casting machine sincethe metal is delivered very easily from the crucible to the mold. Incentrifugal casting machines presently in use which operate about avertical axis it is necessary to exert considerable force merely to liftthe metal up and out of the crucible since the heated metal must bepositioned below the outlet of said crucible prior to the castingoperation.

After the predetermined period of rotation has ended, the operator willmove the door H8 to the right, as viewed in Figure 1, whereupon theelectrical circuit energizing the driving means 56 will be broken byreason of the control button lZfi of switch I28 opening contacts, ofsaid switch. Ihe

rotating portion 22 of the casting machine Ill quickly ceases rotatingand then the operator grips the handles 58 of the large pulley wheel 48and manually causes rotation of the rotatable plate 24 and itssupporting structure 62 into a position wherein pointer H6 on therotatable a plate 24 points to the marker H4 on the stationary part ofthe casting machine ill, assuming that the rotatable portion 22 did notstop in such position at the end of the period of rotation. The

operator then grasps the handles of the cross bar 85 and releases saidbar from teeth 94 and moves it upwardly into engagement with the upperteeth 94 as soon as a platform 14 has passed downwardly to such aposition that the crucible i6 is positioned within the induction coilE02. Downward movement of the platform 14 will also bring the mold intowhich the metal has been cast and has set. The operator will then removethe mold and will fill the crucible with metal and then turn on theinduction coil once again. Then the operations set forth above will berepeated with no time lag.

' Although heating means other than an induction coil may be employedfor heating the crucible for non-ferrous metals, I find that for ferrousmetals the induction coil is very satisfactory from several aspects,particularly, the ability to heat the metal to very high temperatureswhen the casting operationsso require, economy of opera tions andsavings in time. It will be appreciated that the induction coil could bedispensed with and that the crucible '15 could be filled each time froma pouring ladle if it is not necessary to heat the metal to hightemperatures. However, I prefer to employ the induction coil whenferrous metals are to be heated.

Although I have described a preferred form of my invention I do notintend to be limited thereto,'except insofar as the appended claims areso limited, since various changes and modifications will suggestthemselves to others from an examination of my disclosure. I claim:

1. In a centrifugal casting machine having a vertically extendingsupporting structure and a member supported on said supporting structureand rotatable about a horizontal axis, the improvement which consists inhaving the rotatable member an apertured plate-like member, togetherwith a radially movable platform carried on the rotatable member forcarrying both the crucible and mold adjacent each other in castingrelationship with the mold positioned radially outwardly of thecrucible, and heating means comprising a heating coil so disposed as'tointersect the extended axis of rotation of the rotatable memberandhaving its electrical leads passing through the aperture of therotatable apertured platelike member, said radially movable platformbeing adapted to move the crucible and mold toward and away from saidheating coil along a radius of the rotatable aperture member.

2. The improvement of claim 1 wherein the radially movable platform isaperture and is adapted to support the crucible with the main portion ofthe crucible extending from the platform toward the axis of rotation ofsaid rotatable member and wherein the heating coil is an induction coiladapted to encircle said main portion of the crucible with the axes ofsaid crucible and coil being parallel to each other.

3. In a centrifugal casting machine having a vertically extendingsupporting structure and driving means, the combination of a rotatableplate adapted to be driven by said driving means and to be carried bysaid supporting structure and having a horizontal axis of rotation,carrier means carried by the plate and rotatable therewith and adaptedto support a mold and crucible adjacent each other in castingrelationship with the mold positioned radially outwardly of thecrucible, and heating means comprising aheating coil adapted to encirclethe crucible and to melt the metal therein when the coil and crucibleare in a heating position with respect to each other, said heating coilbeing fixedly positioned with respect to the movable carrier adjacentthe center of said rotatable member, and said carrier means beingmovable radially on said rotatable member and adapted to support and tocarry both the crucible and mold with it radially outwardly from thefixed coil at said heating position to a casting position, a dooradapted to be supported by the vertically ext-ending supportingstructure, said door being adapted to be movable toward and away from infront of said heating coil, said rotatable plate and said means forsupporting the mold and crucible, a switch carried by the verticallyextending supporting structure and governing the operation of thedriving means for the rotatable plate, said switch being actuated toclosed position to actuate the driving means when the door is moved toits closed position and said switch being adapted to be opened to shutoff the driving'means by an opening movement of the door.

4. In a centrifugal casting machine having a driving shaft and arotatable member driven thereby, the combination of a carrier supportedon the rotatable member and adapted to support both a mold and crucibleadjacent each other in pouring alignment with the mold positionedradially outwardly of the crucible, and heating means comprising aheating coil adapted to encircle the crucible and to melt the metaltherein when the coil and crucible are in a heating position withrespect to each other, said coil being fixed at said heating positionwith respect to the movable carrier at a location where the heating coilintersects the axis of rotation of the rotatable member, and saidcarrier being movable radially on said rotatable member and adapted tosupport and carry both the crucible and mold with it radially outwardly,from the fixed coil at the heating position, to a casting position whensaid coil and crucible 'art'separated.

5. In a centrifugal casting machine having a driving shaft and arotatable member driven thereby, the combination of a carrier supportedon the rotatable member and adapted to support both a mold and crucibleadjacent each other in pouring alignment with the mold positionedradially outwardly of the crucible, and heating means comprising aheating coil adapted to encircle the crucible and to melt the metaltherein when the coil and crucible are in a heating position withrespect to each other, said coil being fixed at said heating positionwith respect to the movable carrier adjacent the center of saidrotatable member, and said carrier being movable radially on saidrotatable member and adapted to support and carry both the crucible andmold with it radially outwardly, from the fixed coil at the heatingposition, to the casting position when said coil and crucible areseparated.

6. In a centrifugal casting machine having a vertically extendingsupporting structure and a member supported on said supporting structureand rotatable about a horizontal axis, the improvement which consists inhaving the rotatable member an apertured plate-like member, togetherwith a radially movable platform carried on the rotatable member forcarrying both the crucible and mold adjacent each other in cast- 'ingrelationship with the mold positioned radially outwardly of thecrucible, and heating means comprising a heating coil fixedly disposedadjacent the center of the rotatable member and having its electricalleads passing through the aperture of the rotatable apertured plate-likemember, said radially movable platform being adapted to move thecrucible and mold toward and away from said heating coil along a radiusof the rotatable apertured member.

JOHN FREI, JR.

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